How do you solve the system of equations and enter the solution as an ordered pair 7x - 5y = 31 and 4x - 7y = -3?

1 Answer
Apr 8, 2018

Answer:

#x = 8# and #y = 5#

Explanation:

#7x - 5y = 31 color(white)(...)……(1)#
#4x - 7y = -3 color(white)(...) …….(2)#

Multiply first equation by #7# and second equation by #5#
Now, we have

#49x - 35y = 217#
#20x - 35y = -15#

Subtract second equation from first one

#(49x - 35y) - (20x - 35y) = 217 - (-15)#

#49x - 35y - 20x + 35y = 217 + 15#

#49x - 20x = 232#

#29x = 232#

#x = 232/29#

#color(blue)(x = 8)#

Substitute #x = 8# in equation #(1)#

#7(8) - 5y = 31#

#56 - 5y = 31#

#5y = 56 - 31#

#y = (56 - 31)/5#

#color(blue)(y = 5)#